Blumstein studies marmot behavior and communication. He said that when he removed baby marmots from their mothers, they’d elicit “these terrible, horrible screams.”

It got him thinking about dissonance and nonlinearities in sound – like when someone blows too hard on a trumpet and it goes brrrammpppp, or when you turn a stereo up too loud.

“The sound breaks; it becomes unpredictable,” he said.

After giving a public lecture about animal calls, Blumstein was approached by a graduate student who suggested that filmmakers have capitalized on this for decades, putting dissonant music into scores when something exciting or terrible is about to happen.

To test this, Blumstein and the student, Peter Kaye, watched scores of movies. They found that, as predicted, dissonance is used much more frequently in horror movies and action flicks than romance, dramas or comedies.

But whether people actually reacted to the sound was another question.

Blumstein and Kaye teamed up with Greg Bryant, a cognitive psychologist in UCLA’s communications department and the Center for Behavior, Evolution and Culture. Bryant, who is also a musician, created 10-second snippets of music. One sample was just a harmonious, constant ditty. The other, at the five-second mark, became dissonant or distorted.

They then played the tunes for students and found that students who listened to the “control” song rated themselves as unaroused and nonemotional. Those who listened to the dissonant music said they were aroused and maybe sad or fearful.

Then, to see if visual images would have an effect, they showed students a film that tracked with the sound. At five seconds into the film, an action took place, albeit a nonexciting one – such as someone drinking a glass of water or flipping a newspaper page.

Surprisingly, the researchers found that students who listened to the dissonant clip while watching did not rate themselves as aroused.

“It’s probably all about context,” Bryant said. “They were watching something boring and benign, totally not evocative. Then the noise kicks in, and people don’t react because of the negatively benign visual context.”

However, those who watched the film and heard the dissonant movie still had negative valence – they still seemed sadder or more fearful than those who listened to the control music.

Blumstein and Bryant say this is the first study to really look at the functionality of dissonant music – why we like it, are attracted to it or aroused by it – as opposed to the physics of the sound, or how to make the sound. And they’re starting a new project in which they will start to measure people’s physiological response to music.